Automatic yard switch



May 2, 3967 J. L. .JENSEN AUTOMATIC YARD SWITCH .5 Sheetsheet l INVENTOR@f5/,WL Jn/65N ATTORNEYS Filed March 3, 1965 May 2, 395? J. l.. JENSEN3,317,725

AUTOMATIC YARD SWITCH Filed March 5, 1965 5 Sheets-Sheet 2 INVENTOR ly/Vfff/V fj; w

d MVM ATTORNEYS May Z, 3957 .1. 1 JENSEN 3,37,725

AUTOMATIC YARD SWITCH Filed March 3, 1965 3 Sheets-Sheet 5 INVENTOR //A/L q//VSE/v ATTORNEYS United States Patent O 3,317,725 AUTOMATIC YARDSWITCH John L. Jensen, St. Paul, Minn., assignor to Railroad PermanentWay Products Corp., Ashtabula, Ohio, a corporation of Ohio Filed Mar. 3,1965. Ser. No. 436,897 18 Claims. (Cl. 246-445) The present inventionrelates to improvements in railway stub switches of the type in whichthe ends of the moving rails are substantially squarely truncated, asopposed to split switch constructions in which the moving rail ends aresharply pointed. More particularly, the present invention relates to thenovel combination of a unitized prestressed concrete foundation with agreatly simplified stub switch construction to provide a completelywinter proof railway switch that is eminently suited to automaticoperaion.

In stub switches as known in the art, lengths of rail are movablymounted between the approaching and the trailing side of the switch, theswitch or radius rail lengths being adapted to form continuations of thexed rails, and to make connection between the main rails on theapproaching side of the switch, and either the main rails or the siding(turnout) rails on the trailing side of the switch, to the extent thatthey are moved into one position or the other.

Around the turn of the century, stub switches fell into disuse anddisfavor with maintenance men and were replaced with split switchesbecause stub switches, in the forms in which they have been produced inthe past, have been subject to important and very serious disadvantages.Among these disadvantages may be mentioned the objection that the heavystrains and impacts imparted by the cars to the switch, have in thecourse of the wear of the switch, resulted in the stub rails failing tomake perfect alignment between the rails on the approaching and trailingsides of the switch. This failure to make proper alignment or lipping asit is technically called, resulted in accidents and derailments and hasbeen one of the causes of the stub switch being considered unsafe andimpracticable. Another objection to a well known design of stub switchwas that the running rails on each s-ide of the switch crept undertraffic and crowded the switch rails against the xed rails so that theswitch was sometimes rendered inoperable. Another objection common tostub switches was that the switch rails were not always lined upproperly with the fixed rails, and wheels with sharp anges had atendency to climb the rails. Thus, it was very diicult to maintain theold stub switch in good surface, gauge and alignment and theseconstituted important considerations that lead to the decline inpopularity of stub sw-itch constructions. Further, the old stub switchprovided only intermittent tie plate or slide plate support at eachswitch tie and consequently there was no positive means of maintaining aconstant gap distance at the throw point between the ends of the switchrails and the lead and turnout track connecting rails. As the railsexpanded during hot weather, the gap would tend to close, causing abinding condition. In cold weather the gap would tend to become toogreat, thus causing undue pounding and wear.

Accordingly, practically all switches now in use upon the railroads ofthis country are of the knife blade or point type (split switches), inwhich a pair of long tapering rail members are used. Each of theswitching rails is ordinarily about sixteen feet in length and usually,one end of each switch rail is of the same cross section as the trackrails, and is fixedly mounted. This switch rail member is then cut so asto taper gradually to a very thin edge at its free end, and such freeend is movable toward and away from the main track rail for a distancewhich is ordinarily about five inches. Such tapered rails are known3,317,725 Patented May 2, 1967 as points and the switch itself has beenknown as a point, knife blade orsplit switch. In pract-ical use, splitswitches are very unsatisfactory for the reason that they are expensiveto produce in that they consist of a large number of parts which must bemade by special equipment not found in an ordinary machine shop.Moreover, the cutting of rails to form the switch points is an expensiveoperation and the life of the switch points is necessarily short, duesimply to the small amount of material present, thus concentrating thewear. Hence, the thin ends wear rapidly by reason of their small crosssection and frequent renewals are necessary. This is objectionable asthe installation of a split switch and the renewal of worn points isexpensive by reason of the time necessarily consumed in such operations.

Another disadvantage is that the points easily become bent or damagedand this has caused the derailment of trains. For example, if the switchpoints are thrown to permit movement of a train from the main track to-a side track, one of the points is held against a main track rail. Incase a'car should be backed down the main track in the directionopposite to that of the train to be switched, the wheel flanges willpass between the main track rail and the switch point and bend thelatter, whereby it becomes permanently bent or misshaped and the headrod by which the points are operated may also become bent at the sametime. After this has occurred, the switch point cannot be lthrown closeenough to the main track rail to function properly to permit a train tomove on either the main or the side track, but may permit some of thewheels to move along the main track while others are diverted by theswitch point and derailment of the train ensues. The main objection,however, is that the switch points are easily rendered inoperative byice and snow as well as dirt and other foreign substances between theparts of the switch and in particular, between the rails of the switch,such that the switch parts must be cleaned or freed, often atconsiderable expense.

Railroad experience with split switches has shown that in periods ofheavy snowfall and blizzard conditions, operating costs increasesubstantially while at the same time productivity decreases. This is duein great part to the problems encountered with the operation of thepresent split switches. During these periods, it is necessary to sweepthe points of the switches clean before they can be operated. Because ofthe now limited number of track laborers available and the ditiiculty ofemploying temporary help, the switch and engine crews must often spend agreat deal of unproductive time waiting for switches to be cleaned. Theresult is not only increased track-labor costs for cleaning the switchesbut also increased handling costs per car.

Hence, stub switches have the advantage over the split or point switchesnow in general use in that they are not as subject to becoming cloggedwith ice, snow and foreign substances as split-point switches are.Moreover, stub switches are not open to the objection, frequently urgedagainst split or point switches, thatthe extreme end of the switch railis very readily bent or broken.

With these considerations, there is a clearly demonstrated need in theart for an improved railway switch will not only avoid the disadvantagesof the older forms of stub switches, but will also avoidthe'disadvantages of presently known split or point switches.

It is therefore among the principal objects and advantages of thisinvention to provide an improved stub switch which will be safe in useunder the severest conditions of wear; which will not be subject toimpairment by reason of temperature changes or the creeping of therails; which will be capable of withstanding the shocks and strainsirnparted to it by heavily laden railway cars; and which will be of asimple and durable construction.

It is among other important objects and advantages of this invention toprovide a stub switch that will be automatic in operation while solvingthe problem of sweeping out the switches and at the same time reducingthe possibility of derailment.

It is among further important objects and advantages of this inventionto provide an improved stub switch wherein there are no switch points toget out of alignment; wherein there is no jamming from rail creepage;wherein there are no gauge problems; wherein there are no levellingproblems; wherein no stock rails are required; wherein no adjustmentrequiring rail braces are necessary; and wherein spike killed ties areyeliminated.

It is among still other important objects and advantages of thisinvention to provide an improved stub switch having a minimum of movingparts and a novel and rigid foundation that will eliminate mostmaintenance costs; be non-clogging and thus eliminate snow removalproblems; and provide long-lasting, trouble free and safe operation.

Other and further objects of this invention, together with anappreciation for the advantages thereof, will become increasinglyapparent to those skilled in the art as this description proceeds.

Broadly stated, the foregoing objects are achieved and the foregoingadvantages are realized by combining a greatly simplified two rail stubswitch construction with a unitary support, completely eliminating ties.The unitized support comprises a prestressed concrete foundation of onepiece construction for supporting the stub switch construction of theinvention. The improved and greatly simplied stub switch is one in whichthe free ends of two partially xed switch rails are deflected to line upwith either the lead track or the turnout track in order to effect thedesired movement through the switch. Preferably, the switch rails aremounted on the unitized concrete support by interposing sole platestherebetween, and desirably interposing durable rubber rail seatsbetween the sole plates and the unitized support. In this manner, thereis provided a stub switch that eliminates the objections and problemsencountered with the split switch.

More particularly, the objections to tapered or knife blade switchpoints are done away with and the diversion of traflic from main to sidetrack is effected by means of movable track members of largecross-sectional area, preferably equal to that of the main line rails.The present stub switch is mounted on a precast, prestressed concretefoundation instead of switch ties since such a concrete foundationprovides continuous support under the full length ofthe switch. Theconcrete foundation is an integral unit under both switch rails and thusinsures positive track surface and uniform track gauge and alignmentthroughout the length of the switch. The base or sole plates alsoprovide continuous longitudinal support under both rails through theentire switch thus eliminating bjections that have resulted with the useof switch support yby intermittent tie plates and slide plates. Theswitch rails and the lead and turnout track connecting rails are weldedor otherwise securely attached to the continuous sole plates to maintaina constant gap distance at the throw point, thus preventing a bindingcondition or too wide a gap distance between the switch rails and thelead and turnout track connecting rails.

The invention also provides for automatic switch alignment for trailingmovements over the switch wherein the switch track control circuit isdesirably provided with motor driven cam action, known in the art suchas to cause the switch operating mechanism to properly align -the switchrails and lead rails.

The understanding of this invention will now be facilitated as referenceis had to the accompanying drawings in which the same orsimilar-reference numerals have been employed to depict the same orsimilar parts throughout the several views, and `in which:

' direction of movement.

FIGURE l is a plan view illustrating a typical stub switch layoutaccording to the invention, shown connected to broken out sections ofmain and turnout track;

FIGURE 2 is a cross-sectional view taken along line 2-2 in FIGURE 1 toshow constructional details of the prestressed concrete foundation ofthe present invention;

FIGURE 3 is a broken out plan view, greatly enlarged, taken on thesection lines 3 3 in FIGURE 1 to show constructional details of theswitch rail movement connections;

FIGURE 4 is a broken out cross-sectional view, greatly enlarged andtaken on the section lines 4-4 in FIGURE 2 to show constructionaldetails of the switch rail movement connections; and

FIGURE 5 is a modified embodiment of the stub switch according to theinvention showing guides and supports that may be employed therewith.

Referring to the drawings, the numerals 12 and 14 generally designate apair of lead or main line rails, while 12a-14a designate lead or m-ainline rails on the approaching side of the switch and 12t-14t `designatethe main line rails on the -trailing side of the switch, and the nu-`merals 16 and 18 designate a pair of turnout or siding rails. A stubswitch structure designated generally at 10 and constructed according tothis invention is inter'- posed `between the main rails 12a-14a on theone hand and 12t-14t on the other to provide connection to the turnoutrails when desired. The stub switch structure, embodying rails 20 and 22is mounted on a pair of longitudinally tapering steel base or soleplates 24 and 26 which in turn are mounted on lrubber pads (FIGURE 2) 28and 30 interposed between the base plates and the longitudinally andtransversely tapering concrete foun-dation members indicated generallyat 40 and 40 that in turn lare connected together by the transverselytapering concrete cross ties or connecting members 50a and 501. The mainline and turnout rails are supported by the usual ties 11a and 11t, etc.As shown, the left hand ends of the switch rails 20 and 22 may extendbeyond the ends of the supports 4t) and 40', meeting and abutting withthe main line rails 12 and 14a on one of the ties 11a. The right handends of the switch rails 20 and 22 fall short of the right hand ends ofthe supports 40 and 40', such that the right hand m-ain line rails 12tand 14t, as well as the ends of the turnout rails 16 and 118, extendonto and are supported by the right hand ends of the foundation supports40 and 40', reaching almost to the cross-tie structure 50i. The switchrails 20 and 22 are located on the base plates 24 and 26 respectivelysuch that the major portion of each switch rail -rests on its respectivebase plate with the remaining portions extending `beyond the base platesto facilitate standard langle bar connections with the approaching leadtrack rails. For this purpose, hole-s not shown are provided in theswitch rails at their approach ends to facilitate such angle barconnections. Both switch rails 20 and 22 are welded or otherwisesecurely attached for Ia short distance to the base plates at theapproach en-d of the switch. The remaining unsecured portions of bothswitch rails are free to move on the base plates within the limits ofthe rail stops of which four are shown (FIGURE 1) for each switch rail,although more or fewer may -be employed. As shown, the stops 261- 263and 241-243 limit the turnout track direction of movement for the switchrails 20 and 22, respectively, while the stops 262-264 and 241-243 limitthe main line Rail stops are welded to the base plates to limit thedeflection of the switch rails, and are designed to make contact withthe rail web. The stops have rounded or pointed contact surface-s toprevent the accumulation of snow between the web of the rail and thestop.

In the embodiment shown, the switch is connected to the trailing maintracks 12 and 14, and to the turnout tracks 16 and 18 by means of thetwo lead track connecting rails 12t and 14t Iand the two turnout trackconnecting Vtween the rails.

rails 16't and 18t which may be of any rail section as required by therailroad. The connecting rails 12t, 141,`

etc., are located on the respective base plates such that the left handportion of each connecting rail rests on the base plates and theremaining connecting rail portion extends beyond the base plates -at thetrailing end of the switch to facilitate standard angle lbar connectionswith the main tracks 12 and 14 and turn out tracks 16 and 18. It will beIrecognized that small gaps are left between the ends of the switchrails and the connecting track rails to permit smooth movement andaccommodate any iiuctuation in length due to temperature change. Theconnecting track rails 121 and 14t are welded or otherwise secured tothe base plates for the full portion of their length resting on the baseplates. As with the approach side, holes to accommodate standard anglebars for the rail section used are drilled in the connecting rails. Thebase plates 24 and 26 are tapered to Vary in width from the approach endof the switch to the4 trailing end of the switch to provide a solid webor frog plate type support and connection between the corresponding mainand turnout connecting rails. The base plates are securely ate tached byway of anchor bolts 248 and 268 to the concrete foundation whichprovides continuous support under the base plates for their full lengthand width. Rubber rail seat pads 28 and 30 of substantially the samelength and width as the base plates are installed between the baseplates and the concrete foundation.

The concrete foundation is either of precast, prestressed or precastreinforced design. It consists basically of two longitudinal beams 40and 40 which are poured as an integral unit, lbeing connected at twopoints by short reinforced beam sections or cross-ties 50a and 50i. Asshown in FIGURE 2, the precast concrete beams 40 an-d 40 are eachprovided with tapering side portions 42 and a top portion 41.Longitudinal reinforcing rods 45 extend substantially through the entirelength of the beams 49 and 40. The longitudinal Ibeam sections aredesirably tapered in width from top to bottom to provide strong andlstable su-pport for the rails. The anchors for the anchor bolts a-reprecast in the foundation.

Preferably, lateral reinforcing rods 47 are also provided to hold thelongitudinal rods 45 in position, for example, by welding prior topouring of concrete. To this end, the rods 47 may be formed into atrapezoid shape such that all portions thereof are approximatelyequidistant from the respective outside surfaces of the concrete beam.`Cross members 50a and 501 are each composed of upper surfaces 51 withtapering side walls 52. As shown in FIGURE 2, the cross members 51 arereinforced by llateral rods 54 and 55, each of the lateral rods passinga substantial'distance into the beams 40 and 40t. This may beaccomplished, for example, by welding the rods 54 and 55 to the rods 45prior to the pouring of concrete.

Switching is accomplished according to the invention by means of theswitch rod, connecting rod, and clevis members shown. In partcula-r, theswitch control mechanism will drive the switch rod 62 which is connectedby means of the clevis member 63 to the switch rail 20. The switch railconnecting rod 61 is installed between the switch rails a short distanceback from the throwing point ends of the switch rails to maintainstandard gauge be- The connecting rod should have a design oapacity ofat least 5000 lbs. in both compression and tension. The connecting -rodis designed to be adjustable in length and is desirably provided withclevis type connections at the ends. The clevis members may be bolted tothe switch rails by suitably placed holes passing through the webthereof to facilitate attachment to the throw rod. As shown in thedrawings, the switch connecting rod 61 is provided on the other side ofthe switch rail 20 and opposite clevis member 63, the same beingconnected to rail by means of the clevis 64. Connection to switch rail22 is provided by means of clevis 65. As is well known in the art, eachclevis may be comprised of a collar portion connecting two flange-likemembers in a U-shaped arrangement, the flange members having registeringholes for receiving a bolt which will also pass through the eye of asimilar bolt disposed between the ange members.

For the purpose of illustrating` the invention for use with standardAmerican gauge railroads, the overall switch length may be twenty-eightfeet while the switch rails 20 and 22 may be approximately twenty feetin length and may be of any desired rail cross-sectional shape that willmeet the requirements of the railroads. The switch rails may be locatedon the base plates such that about seventeen and one-half feet of eachswitch rail rests on its respective base plate with the remainingportions extending beyond the base plates for purposes already noted,for a distance of about two and one-half feet. The approach ends of bothswitch rails are welded or otherwise securely attached for a distance ofabo-ut three and one-half feet to the ybase plates. The remainingportion, approximately fourteen feet in length, of both switch rails arefree to move on the phase plates within the limits of the rail stops.This is an important feature of the invention as many prior art switcheswere freely hingedly mounted, w-hile others subject. to binding wereusually bolted or clamped in place.

The two lead track connecting rails and the two turnout track connectingrails are about eight andone-half feet in length and may be of any railsection as required by the railroad. The connecting rails are located onthe base plates such that approximately three and one-half feet of eachconnecting rail rests on and is welded-to the base plates, while theremaining 5 feet, more or less, extends beyond the base plates asalready noted. The gap distance between the ends of the switch rails andthe connecting track rails is approximately 1A inch.

The track center for the turnout track at the throw point is 4% inchesmore or less to the left or to the right of the center line of the leadtrack. Both switch rails must therefore Ibe deflected 41A inches more orless at the throw point in order to line up with the turnout trackconnecting rails. The switch rails when deflected for the trunoutmovement through the switch, form a curve with a radius of about 279.64feet along the switch rail arc length of about fourteen feet. The curveradius may be increased by reducing the deection at t-he throw point toapproximately 31/2 inches and using flared guides at the end of thethrow rails as indicated generally by reference ynumerals 74 and 76 inFIGURE 5, For left hand turnouts, the ball of the left lead trackconnecting rail and ball of the right turnout track connecting rail areplaned to provide a throat flangeway distance of about 2% inches betweenthe connecting rails at the throw point. Also shown in FIGURE 5 are aplurality of stop supports 243, 263 which may be used for added supportwhen desired. As will be recognized these are optional featuresaccording to the invention.

The sole or base plates are three-quarters 0%) inch in thickness, abouttwenty-one feet in length and vary in width from about 12%. inches atthe approach end of the switch to about 181/2 inches at the trailing endof the switch. -Each base plate is securely attached to the concretefoundation by approximately thirty-one 3A-inch anchor bolts such thatthe -base plates provide continuous support for their full length andwidth. The spacing and location of the anchor bolts` are shown inFIGURE 1. As an example, the right and left end bolts may be about sixinches from the end of the base plates, while all other anchor bolts maybe on twelve inch centers, although some may be staggered.

The rubber pads are about 1A inch thick and of about the same length andwidth as the base plates. The rail stops are of 3A-inch material and aredesigned to make contact with the rail web.

A switch rod is installed between the switch rails approximately 7inches back from the throwing point ends of the switch rails by means oftwo 11/16 inch holes provided in each switch rail approximately 3 inchesand 1l inches respectively from the throw point to maintain standardgauge between the rails. The -connecting rod should have a designcapacity of at least S000 lbs. in both compression and tension. Theconnecting rod is designed to be adjustable in length and with clevistype shoe connections at the ends.

The concrete foundation, of either precast, prestressed or precastreinforced `design consists of two parallel longitudinal beams, eachapproximately 21 feet in length. The longitudinal beams are 16 inchesmore or less in depth and are tapered in width ranging from about 23inches at the top to 30 inches at the bottom. In contrast to the baseplates, the top and bottom widths of the longitudinal beams arerelatively constant. The cross members are about eighteen inches Wide atthe top and about twenty-five inches Wide at the bottom but have thesame depth as the longitudinal beams, and while the longitudinal beamsmay have stub ends, the cross members, if separable from thelongitudinal members, would have inwardly tapering ends as shown in thedrawings. Preferably, the cross members are parallel to each other andperpendicular to the longitudinal beams. The cross members may bedisposed about three feet six inches to about four feet four inches fromthe longitudinal beam ends, measuring from top surfaces, and the crossmembers may be about ten feet two inches apart also measuring from thetop. Viewed from the top, all sides taper according to the preferredembodiment such that the bottom is about three and one-half inches away.Since the rail gauge is four feet and eight and one-half inches, thelongitudinal beams will be about two feet ve inches apart along theirinside base edges, and about seven feet ve inches apart at their outsidebase edges. i

The longitudinal beams are provided with a plurality of longitudinallyextending steel reinforcing cables or rods 45 which are prestressedprior to or after the pouring of concrete to form the beam. Theprestressed cables or rods 45 are each prestressed for exampleto atension of 14,000 pounds for longitudinal beams. Instead of the members47, the longitudinal beams may be additionally reinforced with a No. 5gauge steel lspiral tie 48 (FIG- URE 4) having a 6-inch pitch providedover the full length of the beam, the spiral ties preventing lateral orvertical misalignment of the prestressed strands of cables or rods 45.After the cables or rods 45 have been bonded into position by the spiralties 48 on the 6-inch pitch throughout the length to which the beam isto be made, the concrete is poured into the form and the beam is cast.

By carefully controlling the mix of concrete, a minimum compressivestrength is placed on the beam by prestressing cables or rods 45 in theamount of 5000 pounds per squ-are inch after 28 days whereas theultimate prestress loading of thefinished beam is 727 pounds per squareinch. If the beams are to be used for railroad use they have a verticalheight of 16 inches Whereas if the beams are to be used in an urbanrap-id transit system they may have a vertical height of only 8 inches.

The concrete cross beams 50a and S0t are also prestressed and -precastand provided with a plurality of prestressed reinforcing lsteel rods orcables 54 and 55, which are suitably placed in the prestressing formprior to pouring of the concrete. The rods 54 and 55 extend through thelength of the cross beams and project out of each end of the same. Therods 54 and 55 are then welded to the rods 45.

While the drawings disclose the cross :beams as having a vertical heightapproximately the same as the height of the longitudinal beams it is, ofcourse, within the scope of the present invention that the cross beammay have different heights than the beams 40V and 40. While -any desirednumber of cross beams 50a and 50t may be used between a pair of thelongitudinal beams, it has been found that two of such cross beamssuitably anchored to the respective longitudinal beams are suicient toprovide 4adequate strength and sufcient rigidity to the supportingstructure for the traction rails and switch movement. Since thelongitudinal concrete beams are supported along their full length by theusual type of railroad bed, the shear on the longitudinal beams isnegligible and it has been found that such beams are capable of carryingat any one point 61,700 pounds, which provides a considerable margin ofsafety lbeyond the amount of stress normally encountered.

The present stub switch may be driven (thrown) or operated by any of thepresently approved switc-h machines, including those mounted between thetracks as indicated by reference numeral 71 in FIGURE 5, which switchesmay employ air cylinders; hydraulic cylinders; a screw dock devicedriven by electric or air motors; an eccentric cam driven by gear motor;or by any other desired means, such as any suitable manually operatedswitch thro-wing device.

As an example, the presently installed switch may be operated by a UnionSwitch & Signal VM--l switch machine. However, various other methods ofoperation are also suitable as Will be hereinafter appreciated. Thetrack circuitry is so designed that the track-fouling circuit willactuate the switch mechanism to properly align the switch for a trailingmovement over the switch. If the electric current should be interrupted,the machine can be overridden and the switch thrown by hand. This switchwill perform satisfactorily without the need for sweeping snow from it,even under severe snow conditions land very heavy switch movements.

As another example, the improved stub switch according to the inventionwas employed in a suitable testing installation. The two switch railswere each welded to 3i-inch thick base plates mounted on the prestressedconcrete foundation instead of on switch ties. A one-quarter inch thickrubber pad was installed between the base plate and the foundation. Thebase plates extended the full length of the twenty-one foot concretefoundation and were anchored securely to the foundation.

Each switch rail was 17 feet 4 inches long and each was welded to thebase plate at one end such that each was movable at the other end for adistance of twelve feet. The free end had a 41/2-inch throw and wasprovided with a ared guard as shown in FIGURE 5, eighteen inches inlength and disposed on the gauge side to provide a norm-al flangeway forwheels. The fixed rails, which were welded to the base plates andseparated from the switch rails by one-quarter inch gaps, were about tenfeet long and were machined to provide a standard flangeway. The weldingprevented the xed rail from crowding into the switch rail. The `systemwas entirely satisfactory with all types of rail traic, even under heavysnow and ice conditions.

It is thus evident that the present invention overcomes the defects ofprior art split and stub switches. For example, it is a familiar fact tothose acquainted with the workings of railways that the shrinkage andexpansion of the rails, caused by variations of temperature, seriouslyaffect the operation of present switches. The switch rails, not beingconnected with the ties, are moved endwise bodily by the xed railswhenever expansion and contraction occur, thus making the play betweenthe ends of the rails at the switch-joint greater than at any otherjoint. In consequence of this, and in view of the fact that the slippingof the so-called fixed rails on the ties and at the joints is extremelyvariable, it is dilcult to settle upon just the proper movement to allowfor at the switchjoint. The result is that the rails are apt to jam atthe switch-joint, so that they cannot be readily moved unlessconsiderable space is allowed, in Which case, when the rails arecontracted, they are apt to be drawn off the headblock, or at least tobe crushed or splintered by the hammering of the wheels. Moreover, ifthe rails are loosely jointed, the traction of the engine wheels tendsto drive them endwise and jam, or cause a gap at the switch-joint, asthe case may be. However, the switch construction of the presentinvention remedies these defects, and provides a switch that willoperate freely at all temperatures with the minimum play at the joints,as well as enjoy other advantages already noted.

It will be recognized that a stub switch constructed according to thepresent invention has been described and shown only by way of example inthis specilication and in the accompanying drawings, and it should beunderstood that the form described and shown is not the only one inwhich the invention may be embodied, and that changes may be made in theconstruction which is described and shown without exceeding the scope ofthe invention except as defined in the appended claims. Having thusdescribed the invention, what is claimed as new and desired to besecured by Letters Patent is:

What is claimed is:

1. A stub switch construction comprising: a precast and prestressedconcrete foundation, the concrete foundation providing an integral andunitary support for the switch construction to thereby insure positivetrack surface and uniform track gauge and alignment throughout thelength of the switch; a pair of continuous longitudinal base platesdisposed upon said concrete support; and a stub switch rail disposedupon each longitudinal base plate, a portion of each switch rail at theapproaching end of the switch being xedly secured to the respectivelongitudinal base plate, the remaining portion of each switch rail beingfreely movable from a position adjacent the rails of a main rail line onthe trailing end of the switch and a position adjacent the rails of aturnout track on the trailing end of the switch.

2. The stub switch construction of claim 1 including rubber padsinterposed between the top surface of the concrete foundation and eachlongitudinal base plate.

3. The stub switch construction of claim 1 including switching meanscomprising a connecting rod disposed between each of the stub switchrails, said connecting rod being connected to the respective stub switchrail by means of a clevis member; and a switch throw rod connected toone of said stub switch rails by means of a clevis member, the switchthrow rod being responsive to a switch control and driving mechanism.

4. A stub switch construction comprising: a prestressed concretefoundation; a pair of base plates mounted on said foundation; a stubswitch rail mounted on each base plate; a portion of each stub switchrail being welded to the respective base plate, each base plate beingsecurely anchored -to the concrete foundation; a rubber pad disposedbetween each base plate and the concrete foundation; and a plurality offixed rails disposed at either end of said stub switch construction.

5. The stub switch construction of claim 4 wherein the base plates aresteel of about three quarters of an inch in thickness.

6. The stub switch construction of claim 4 wherein the base plates andconcrete foundation are each about twentyone feet long.

7. The stub switch construction of claim 4 wherein the rubber pad isabout one quarter inch in thickness.

8. The stub switch construction of claim 4 wherein the stub switch railsare shorter than the concrete foundation such that a portion of at leastsome of the fixed rails are disposed on said concrete foundation.

9. The stub switch construction of claim 4 wherein each stub switch railis approximately seventeen to twenty feet long.

10. The stub switch construction of claim 9 wherein approximately twelveto fourteen feet of the stub switch rails are freely movable.

11. The stub switch construction of claim 4 wherein the free ends of thestub switch rails have a throw of approximately three and one half tofour and one half inches.

12. The stub switch construction of claim 4 including a flared guidedisposed on the gauge side of at least one stub switch rail to provide anormal angeway for wheels.

13. The stub switch construction of claim 12 wherein each flared guideis approximately eighteen inches long.

14. The stub switch construction of claim 4 wherein the lixed rails areapproximately ten feet in length, are separated from the switch rails byapproximately one quarter inch gaps, and are machined to provide astandard iiangeway.

15. The stub which construction of claim 4 wherein the prestressedconcrete foundation comprises: two parallel longitudinal members, andintegral therewith and disposed at right angles thereto, two parallelcross members, each cross member being separated one from the other andfrom the ends of the longitudinal members.

16. The stub switch construction of claim 15 wherein both longitudinalmembers and cross members have tapering side edges.

17. The stub switch construction of claim 4 wherein the concretefoundation is reinforced with steel rods.

18. The stub switch construction of claim 4 wherein the base plates andrubber pads taper in width from the approaching ends to the trailingends of the switch.

References Cited by the Examiner UNITED STATES PATENTS 109,141 11/1870Miner et al. 246-447 745,199 l 1/ 1903 Koch 246-447 1,818,145 8/1931Macnier 238--115 ARTHUR L. LA POINT, Primary Examiner. S. B. GREEN,Assistant Examiner.

1. A STUB SWITCH CONSTRUCTION COMPRISING: A PRECAST AND PRESTRESSEDCONCRETE FOUNDATION, THE CONCRETE FOUNDATION PROVIDING AN INTEGRAL ANDUNITARY SUPPORT FOR THE SWITCH CONSTRUCTION TO THEREBY INSURE POSITIVETRACK SURFACE AND UNIFORM TRACK GAUGE AND ALIGNMENT THROUGHOUT THELENGTH OF THE SWITCH; A PAIR OF CONTINUOUS LONGITUDINAL BASE PLATESDISPOSED UPON SAID CONCRETE SUPPORT; AND A STUB SWITCH RAIL DISPOSEDUPON EACH LONGITUDINAL BASE PLATE, A PORTION OF EACH SWITCH RAIL AT THEAPPROACHING END OF THE SWITCH